Field of the Invention
The present invention relates to a calibration auxiliary device of an on-vehicle camera which is mounted on a vehicle.
Description of the Related Art
In a front monitoring camera or an environmental monitoring camera mounted on a vehicle as a device of one of advanced driver assistance systems (hereinafter referred to as ADAS), functions of accurate calculation of positional precision or detection such as vehicle detection, pedestrian detection and white line detection are reduced when an optical axis position of the camera is deviated due to lapse of time and so on. In response to the problems, there is proposed a calibration device including an extraction section extracting a feature point of a vehicle from a contour image of the vehicle taken by an on-vehicle camera, an estimation section identifying a lens center point of the on-vehicle camera and a point on an extension line passing through the feature point, a storage section storing the lens center point of the on-vehicle camera which is mounted on the vehicle at an ideal position and in an ideal direction, and an ideal point on the line passing through the feature point, and an adjustment section adjusting the on-vehicle camera so as to minimize the distance between the point on the extension line and the ideal point (refer to Patent Document 1).
[Patent Document 1] JP-A-2014-174067
However, in the above related-art calibration device, there are constraints that part of the vehicle to be a feature point has to be captured on an angle of view of the on-vehicle camera, and that part of the vehicle to be the feature point has to keep the relationship of an absolute position with respect to the position of the on-vehicle camera. Therefore, there is a problem that it is necessary to set the camera so as to satisfy the above constraints at the time of setting the camera, which reduces the degree of freedom in setting the camera. There is also a problem that a detection area to be detected is narrowed for capturing part of a vehicle body within a detection range of the camera. That is, in the case where part of the vehicle as the feature point is deformed or damaged due to some reasons, ideal calibration operation is not performed. Furthermore, it is necessary to incorporate the calibration device in an electronic control unit (hereinafter referred to as ECU) for controlling the on-vehicle camera in order to realize the above related-art calibration device, and there is a problem that it is difficult to be applied to an existing on-vehicle camera system which has been commercially available.